r How to remove some parameters from the legend in ggplot2

September 29, 2022

Sorry, couldn’t find the answer among the existing threads, so creating the new question for that.

I’m wondering how to remove from the legend some particular parameter used for grouping (but without removing the legend completely) in ggplot2.

Let’s say, I’m creating this graph:

ggplot(mtcars, aes(x= factor(cyl), y= hp,
                   fill= factor(am), shape = factor(carb))) + 
  theme_bw()+
  scale_shape_manual(values= c(20:25))+
  geom_boxplot(alpha = 0.5)+
  geom_point(position=position_dodge(0.76), size = 4)

And I want to show the legend only for factor(am), but to remove factor(carb).
How would I do that ?

Thanks a lot for the help!

>Solution :

You can specify guides(shape = guide_none())

ggplot(mtcars, aes(x= factor(cyl), y= hp,
                   fill= factor(am), shape = factor(carb))) + 
  theme_bw()+
  scale_shape_manual(values= c(20:25))+
  geom_boxplot(alpha = 0.5)+
  geom_point(position=position_dodge(0.76), size = 4) +
  guides(shape = guide_none())